Generally, wireless communication systems use microwave frequencies in the range of approximately 2 to 10 Giga Hertz (GHz). Conventional wireless communication systems, however, use frequencies with a relatively long wavelength such that these wireless communication systems mainly employ omnidirectional or low-directivity antennas. Examples of such communication systems include those conforming to the Worldwide Interoperability for Microwave Access (WiMAX), 3rd Generation Partnership Project Long Term Evolution (3GPP LTE).
With the gradually increasing demand for high transmission rates, systems using frequencies in a millimeter wave band are being taken into consideration. Compared to microwave frequencies, the millimeter wave band can provide a relatively high transmission rate. But, because attenuation increases with higher frequency, a high-directivity antenna or a beamforming technique is often used.
Generally, prior to communication, a terminal and a Base Station (BS) performs a network entry procedure. The network entry procedure includes processes of downlink synchronization acquisition, system information acquisition, time offset, frequency offset, power adjustment, and the like. When performing the first network entry, the BS and the terminal cannot determine an optimal beam vector due to lack of knowledge the others whereabouts. Accordingly, upon initial access, proper signaling performance may be difficult to achieve.
Accordingly, an alternative for improving the signaling performance in an initial network access process should be provided.